FOURTEENTH ANNUAL YEAR BOOK— PART X. 745 



to the cleaning, disinfection, and drying of the incubators and brooders 

 before tliey are again used. It is probable that this disease is generally 

 due to failure to maintain a proper degree of cleanliness. 



Gapes. — ^Gapes is a disease of chickens which develops during the first 

 few weeks of their lives and is made evident by frequent gaping. It is 

 caused by a parasitic worm {Syngamus trachealis) which attaches itself 

 to the internal surface of the windpipe, sucks blood from the mucous 

 membra'ne, and obstructs the passage to such an extent as to interfere 

 seriously with the breathing. The insufficient supply of air, the loss of 

 blood, and the diminishing activity in looking for food lead to a weak 

 and bloodless condition and often to death from overcrowding or ex- 

 posure that a well chick would be able to resist without injury. Some- 

 times so many worms accumulate in the windpipe that breathing be- 

 comes impossible and the chick dies from suffocation. 



Causation. — The worm which causes this disease is sometimes called 

 the red worm or the forked worm because of its color and of the fact 

 that the male and female are so firmly grown together that they cannot 

 be separated without tearing the tissues. The two worms united in this 

 manner appear at first sight like a single worm with two necks and two 

 heads. The female is a little more than one-half inch in length and the 

 male one-fifth inch. The heads of both are attached to the mucous mem- 

 brane, irritating it to such a degree that there is an increased secretion 

 of mucus, which collects and increases the difficulty of breathing. 



A large number of eggs develop in the female worm while in the 

 windpipe, and these are either thrown out by the chick while sneezing or 

 they are swallov/ed, pass through the stomach and intestines unharmed, 

 and are scattered with the droppings. These eggs adhere to the food or 

 get into the drinking water and thus infect other chicks and keep up 

 the disease indefinitely. Often the red worms are coughed up, but they 

 are immediately seized and swallowed by some of the chicks, and in this 

 manner also the disease is spread. 



The eggs of this worm live a long time in the soil and are sometimes 

 taken into the digestive tube of earth worms. In badly infested ground 

 a considerable proportion of earthworms may, if eaten, be capable of 

 causing the disease in chicks. 



These facts explain why ground upon which chickens are raised year 

 after year becomes so badly infested, and how the infection is carried 

 over from, one year to the next. It seems that the worms may also be 

 carried by grown fowls and by some wild birds and that this is anotlier 

 means for their preservation. 



When the eggs of this worm are taken into the stomach of the chicks 

 the young worms are soon liberated and find their way in a few days to 

 to the windpipe, where they may be seen already attached within a week. 



8ijmptoms.— The symptoms of gapes are most frequently observed in 

 chicks from 10 days to 4 weeks old. The affected birds cough or sneeze 

 with an abrupt, whistling sound and a more or less labored effort. Very 

 soon they begin to gape, extending the neck and opening the beak, thus 

 indicating that they are not getting a sufficient supply of air. During the 

 first few days the appetite is ravenous, but in spite of the quantity of food 

 eaten the birds become weak, anemic, and emaciated. Later there is little 



